Study Finds Coordinated Off-peak Charging Can Support Large Scale Plug-in Use Without Additional Generation Capacity; TCO and GHG Abatement Costs for BEVs Projected to Remain High

18 October 2010

Examining the potential impact of large-plug-in vehicle use in the context of the Netherlands, a study by Oscar van Vliet at the International Institute of Applied Systems Analysis and colleagues at Utrecht University concluded that, if off-charging is successfully introduced, electric driving need not require additional generation capacity, even in the event of a 100% switch to electric vehicles.

The study, in press in the Journal of Power Sources, examines the efficiency and costs of current and future EVs, as well as their impact on electricity demand and infrastructure for generation and distribution, and thereby on GHG emissions.

We therefore examine the feasibility of electric driving taking into account not only drivetrain choices, but also driving patterns, changes in the electricity mix, charging patterns, and energy losses in relevant parts of the WTW chain. There are three main aspects to this analysis:

Determine the effect of EV charging patterns on household and total electricity demand.

Derive GHG emissions and costs of charging of EVs in the 2015 Dutch context and
beyond.

Compare GHG emissions and costs of PHEV and BPEV with those of regular cars.

“As lifestyles, working hours and household technology are fairly similar across industrialised
nations and households, demand patterns without EV charging should be fairly consistent,
except for higher use of air conditioners in the daytime in warmer climates. We therefore
expect our findings on the impact of charging patterns on demand to be applicable to
industrialised countries. ”

—van Vliet et al.

All reference car configurations except the diesel use gasoline engines, because the
purchase cost of gasoline engines is some €1500 lower than of diesel engines. The team assumed
that gasoline engine-generators in SHEVs and PHEVs have the same efficiency relative to diesel
generators as gasoline engines relative to diesel engines in regular cars. They also
assumed a shift from current central motor (CM) drivetrains to wheel motor (WM) drivetrains
from 2015 onwards because higher efficiency of wheel motor drivetrains allows for smaller
and cheaper engines and battery packs.

They assumed an oil price of US$80/bbl, close to the short-term
projections in the World Energy Outlook 2009.

They used an EV drivetrain with a single 74 kW central motor (CM) that consumes 103±20 Wh/km from 2010 and one with two 29kW wheel motors (WM) that consumes 89±19 Wh/km from 2015. In hybrid car configurations, these are powered by a gasoline-fuelled engine-generator that produces 53 kWe
for a CM drivetrain and 46 kWe for a WM drivetrain with an efficiency of 31%. Building on the SHEV drivetrains, they assumed PHEVs with an electric range of 50 km (31 miles) and
BPEVs with a range of 250 km (15 miles).

They used Li-ion batteries with a cost of €960/kWh in 2010, and assumed this reduces to €800 /kWh around 2015, and to €400/kWh in the more distant future. The Li-ion batteries have a specific energy of 86 Wh/kg, assumed to increase to 110 Wh/kg around 2015 and to 150 Wh/kg in the
more distant future. They used a depth of discharge of 70%.

Among their findings:

Uncoordinated charging would increase national peak load by 7% at a 30% penetration rate of EVs and the household peak load by 54%, which may exceed the capacity of existing electricity distribution infrastructure. At 30% penetration of EVs, off-peak charging would result in a
20% higher, more stable base load and no additional peak load at the national level and up to
7% higher peak load at the household level.

GHG emissions from electric driving depend most on the fuel type (coal or natural gas) used
in the generation of electricity for charging, and range between 0 g/km (using renewables) and
155 g/km (using electricity from an old coal-based plant). Based on the generation capacity
projected for the Netherlands in 2015, electricity for EV charging would largely be generated
using natural gas, emitting 35-77 gCO22 eq/km.

The total cost of ownership (TCO) of current EVs are uncompetitive with regular cars
and series hybrid cars by more than €800/year. TCO of future wheel motor PHEV may
become competitive when batteries cost €400/kWh, even without tax incentives, as long as
one battery pack can last for the lifespan of the vehicle. However, TCO of future battery-powered cars is at least 25% higher than of series hybrid or regular cars. This cost gap
remains unless cost of batteries drops to €150/kWh in the future. Variations in driving cost
from charging patterns have negligible influence on TCO.

GHG abatement costs using plug-in hybrid cars are currently 400 to 1400 €/tonne CO
may come down to -100 to 300 €/tonne. Abatement cost using battery powered cars are
currently above 1900 €/tonne and are not projected to drop below 300-800 €/tonne.

We find that EV can be integrated into the Dutch grid with few additional investments apart from coordinated chargers. Using PHEV, this need not increase the cost of driving
significantly and could reduce emissions from driving by more than 70% compared to diesel
and petrol cars and by more than 55% compared to other hybrids that use petrol. We therefore
recommend further development of electric drivetrains and batteries for use in SHEV and
PHEV.

With respect to the possible future deployment of EV, we recommend further research into
combining CHP with EV charging, effects of EV charging on local electricity distribution
grids, cost developments of batteries and chargers, and the effect of driving patterns and
different vehicle classes on EV fuel consumption. We also recommend integrating WTW
analysis with analysis of energy and GHG emissions from EV manufacturing, as well as
impacts of EV on non-GHG emissions, and investigating the possible role of EV in
conjunction with other car alternatives, low or zero carbon fuels and green electricity in
reducing GHG emissions.

Comments

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This is perfect! Rather than let utility companies meet demand by building safe, clean, nuclear power plants, incompetent governments should come in and make it illegal to charge your EV when you need to charge it. Drive to work - EV can't get you home due to its 30 mile range. Sorry, you'll have to stay overnight because it is illegal to place additional demand to the power grid during peak times.

Well managed PHEV/BEV charging systems can regulate (even, level, flatten) power stations and electrical distribution grid loads and greatly increase their overall efficiency. This should translate into lower electricity price for everybody, at least until such time as authorities have to add an extra e-tax to compensate the lost of fuel taxes.

The extra power generation plants will be required because there is a lot of power available (and not current used) during over 12 hours a day.

Somebody will always have to pay to build and maintain roads and bridges.

In our area, Hydro power load varies between 40,000 megawatts during peak hours (on very cold winter days between 06:30h and 09h and again between 16h and 20h) to as low as 12,000 megawatts at night time when BEVs and PHEVs could be recharged. There is also lots of power available between 09h and 16h. The 3 to 5 KWh required to recharge a PHEV/BEV overnight is nothing compared to the power we use for heating, hot water, dryers, cooking etc. Turning down electric heating while at work and at night liberates more than enough electricity for 2 PHEV/BEV. Programmable electronic thermostats already do that automatically.

If your car needs charging during the day while shopping, or during your drive to work, it means:
1) you forgot (or were too lazy) to plug it in last night
2) you live way too far from work and shouldn't be using an EV
3) your car battery is way undersized

That's why I think it is a bad idea to populate a city with charging centers - it just encourages bad charging behavior.

Once again the study totally ignores the energy cost (drilling + retrieving[pumping]+ refining + transporting + delivering) of fossil fuels. Doing a well to wheels comparison on EVs versus tank to wheels is completely biased and irresponsible. It is estimated that it costs 8 gallons of gas for every 10 delivered, or effectively a 30 MPG car actually gets only 16MPG with the true energy cost. So in reality, the numbers are actually closer to reducing GHG by 127% when comparing gas or diesel vehicles to EVs.
It is interesting to note that even when biased unfairly against EVs as this study (and most like it) is, EVs still come out significantly better than fossil fuel ICEs. When the equation is truely balanced, it's no contest.

There is no problem populating cities with charging stations, just charge 2x or 4x the consumer price for power.
Anyway, they are proposing PHEVs, which can run on liquid fuels anyway.
No problems here, just advise people to charge at night and let them at it.

What would be interesting would be a graph showing the cost/benefits as you add KWh to a PHEV battery.

My view is that very small battery PHEVs (like the next Prius) will be the sweet spot for at least 10 years, or until they get the battery cost down.

When I had an '06 Prius, the battery would often get discharged to the lower limit, and I wished I had a bigger battery and a means to charge it at home.

With the '10 prius, the battery virtually never gets to the "low discharge" state. Toyota has done an amazing bit of engineering. I'm not sure what the optimal way of integrating a higher capacity battery in the Prius would be. Maybe more low speed all electric driving?

We all knew that there is spare capacity off-peak to power a substantial, perhaps 50% of the auto fleet, without needing to add new capacity.

But a very large portion of that spare capacity is very old, antiquated, dilapidated, and polluting.

When the unthinking Greens took over from the principled Nuclear critics, and indiscriminately started forcing plant cancellations, the only recourse was to keep old coal plants running. Thanks to the further stupidity of the Carter Greens, grandfathering in old pollution belching generation, we continue to have those old plants running with little emission controls.

I look forward to the coming Nuclear Renaissance entering the cement pouring phase, as an opportunity to retire and scrap lots of those "old Smokers",as wa splanned to do back in the 1970s and 1980s. Not only will the new Nuclear plants reduce and replace a significant percentage of coal generation, it will cause the Utilities to scrap the oldest, worst, and most dirty plants, so the improvemnt will be outsized.

It is less than 15 months to the final NRC approval for both the Westinghouse and GE "standard plant" designs. It has taken over 5 years to propose, revise, rework, and redesign, and then approve every joint, valve, circuit, pipe, and component by genuine engineers, on both sides. The new Gen III+ "standard designs" are the better for it.

More importantly, the green lawyerly critics will have lost their legal standing to sue, stop work, and delay construction, bankrupting the Utilities. Construction of a "standard design" will continue unless critics can convince the NRC's approving engineers that their criticism is valid instead of some ignorant, non-understanding, Judge, without a technical clue.

Only if the panel of NRC engineers doing the review agree, will construction cease for rework. But that eventuality is unlikely, given the "standard designs" have been approved in detail by NRC engineers, but near "standard designs", are also built and are operating overseas.

The world will be pleasantly surprised when 30-odd new nuclear plants start coming on line in the US, on budget and on time, in 3 1/2 years after first concrete is poured.

Stan: Your description of USA's power plants represents reality in a country where the guiding objective is maximum profits at all cost.

Fortunately, it is not the case everywhere.

Our Hydro power plants and distribution grid are relatively recent, non-polluting and in good working order. Power failures are almost non-existant and power shortages do not exist. The existing Hydro (40,000+ megawatts) could be doubled in the next 30 years or so. Concurrently, the undeveloped potential 95,000 megawatts wind power could contribute progressively more in the near future. The total (Hydro-Wind) could reach (80,000 + 80,000 = 160,000 megawatts) by 2100-2150. Eventually, wind could become the primary power source with adjustable hydro as back-up or for peak demands.

USA has neglected to properly and effectively regulate e-power generation for decades. Yes, 50 to 100 new, safer, nuclear plants + upgraded grid may become a must soon. Meanwhile, a few hundred NG, solar, wind, power plants could help to replace outdated polluting coal fired plants.

I guess the problem of EVs in Canada is low temperature driving.
The waste head from ICEs can be used to heat cars in cold places.
With efficient EVs we have much less waste heat, so unless we install kerosene heaters, we have a problem.
Ironic, really.
Like the problem of LED traffic lights and snow.

There is no such thing as a free lunch, and you still have to be careful with cheap lunches.

Actually batteries also generate waste heat when charging or discharging so as long as your BEV has an insulated battery box driving in cold weather should not be a problem. And neither should the start-up if the battery box has an e-heater that's powered by the same plug that's recharging your car while it's parked.

OTOH as many places in Canada do have very cold winters we've seen fit to install block heaters on our cars, and outlets at parking spaces, in those places: So a lot of the infrastructure for BEVs is already there.

Limited-range PHEV that is charged during the day time at the work place is actually a good idea. It will encourage more roof-top solar PV panels that can sell its power to the grid. No need for expensive lead-acid battery storage for PV panels in order to charge your BEV at night from the solar energy collected during the day time.

What about in the winter time, when solar energy will be much less abundant?
Winter use of PHEV is more biased toward ICE use to provide cabin heating, wind shield defrosting, and keeping the battery warm, so less energy will be drained from the battery.
Furthermore, installation of small CHP (Combined Heat and Power) generators at the workplaces can provide both electricity to charge the PHEV's during the day time and the heat to keep the workplace warm.
Likewise, CHP at home can provide excess electricity to charge the BEV or PHEV as well.

At any rate, with more and more BEV's and PHEV's that will be plugged into the grid both day time and night time, we will have the opportunity for V2G load-leveling that will make the grid much more stable and will allow more efficient electrical generation than is possible now. It will be a win-win scenerio, if well-managed and well-coordinated.

I think ER1EV (PHEV) up to 40 miles electrical with small biofuel range extender would be practical solution. The study demonstrates that as well. Drive 80% of distance electrical and 20% using domestic biofuel, indefinite driving distance and max. driving comfort, no additional investment into power infrastructure. One thing bothers me - too slow start of mass production. First hybrid Prius stroke market in 1999. Now only 2 mln. hybrids on world roads. No pug-in on the sale yet. How long it would take to make more or less significant impact from any perspective. It should be at least 100 mln. in the world to constitute 20% fraction. Study presumes, that some time EV powertrain will be 100% dominant. At current speed of market penetration it would take 100 years.

If you have abundant hydro (say Canada or Norway), you can slap in loads of wind or solar.
If you don't have hydro, balancing the wind/solar becomes a big problem.
In Ireland, we have about 1800 MW of wind on the grid.
On some days last week, we had between 4 and 40 MW, or less than 2.5% availability - for the whole day.
If you have 6 months electricity sitting behind a dam, that is no problem, but if you don't, you have to think about the viability of it.
You are building monuments, rather than electricity generating capacity.

Actually mahonj the Germans have already shown you don't need abundant hydro to "slap in loads of wind or solar."
http://www.solarserver.com/solarmagazin/anlagejanuar2008_e.html
http://www.youtube.com/watch?v=aNZgjEDPe24
http://www.kombikraftwerk.de/fileadmin/downloads/Technik_Kombikraftwerk_EN.pdf

Please note that in this test they had +22 MW of regionaly dispersed wind, solar and biogas power plants to just 1.06 MW of hydro. That's better than 20 to 1. And the hydro wasn't even "run-of-river" hydro but just pumped storage. The real key to balancing the wind/solar loads was the biogas and the regionaly dispersed wind/solar, and what little storage they did use could have been handled by any number of other systems; like V2G or Compressed Air Energy Storage (CAES).

I'm thinking that the problem you're having with the variability of wind in Ireland is you haven't got enough variation in the power plants: 1800 MW of wind turbines but not solar nor biogas? and as Ireland is smaller than Germany (a fourth the size???) the wind might be too concentrated; http://www.iwea.com/index.cfm/page/windmap

Wind is a perfect companion for Hydro due to the availability of the huge water reservoirs for energy storage and the easy variation of hydro output when required. To maximize wind power usage you may have to make it the primary power source and use hydro for fill in on an as required basis. Hydro people have difficulties with being in second place to wind power and are fighting it.

Wind and Hydro are sustainable clean power sources and will be around for centuries or as long as we are around.

Less than 50% of the world hydro potential is currently being exploited.

Les than 1% of the world wind potential is currently being exploited.

Less than 0.1% of the world solar potential is currently being exploited.

The world does not need limited fossil fuel to produce clean electricity.

But wind and solar is far less economical than EV. You have to subsidise them heavily. At least 70% of electricity price paid to wind farms is subsidy. In photovoltaic case is even worse. So in case EV subsidy $7500 per automobile is best result in green area. May be ethanol is getting close to be competitive as well not taking into account that oil price is speculative with processing cost being much less.
I think the most realistic patter of development is coal power plant efficiency inprovment with clean up and restart on nuclear. Wind power would get closer being more economical in areas where it is possible achieve 50% availability.

Yes, solar in Ireland is possible. Direct sunshine is
intermittent and unpredictable in Ireland, making high temperature applications (concentrating solar
power) for electricity generation impracticable but PV solar can work with indirect sun. The annual average global insolation (the amount of energy reaching the surface per square metre) values for Ireland range from 2.6 – 3.0 kWh/m2/Day. A surface area of one square metre receives approximately 900 – 1000 kWh of solar energy per year. (The equivalent energy in 100litres of oil.) Ireland receives higher solar radiation levels than most areas in the UK.

However Ireland really shines in biomass; being in the path of the Gulfstream in has a great growing season. "Ireland’s potential to develop biomass for energy is exceptional. Ireland has the best growth climate in Europe based on Paterson’s Climatic Index. Ireland’s land area is approximately seven million
hectares, of which 4.3 million hectares are used for agriculture and roughly 710,000 hectares for
forestry. The largest source of wood biomass is in the national forest estate, where a potential of 0.5
million tons of wood is recoverable for energy use, with an equivalent energy value of 200,000 tonnes of
oil. In addition to the biomass resource, there are several by-products of farming and food processing which can be utilised as biofuels. These consist of animal by-products, tallow, animal manures and food
by-products. It is estimated that approximately 70 MW of electricity can be generated annually fromwaste biomass."